I have a 1974 Ford 4000 tractor with power assist power steering. It started leaking fluid up the steering column. Iam having trouble putting it back together. I am ready to reinstall the steering shaft into the ball nut. how does the control valve come apart so I can install the bearing races into the bearing housing after I install the shaft into the ball nut? My shop manual shows the valve pulled apart but doesn't explain how to dissemble it so the races for the steering shaft bearing can go into the housing.